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Finding the Fourth Proportional to 390.60, 585.90 and 130.64

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Solution

The fourth proportional to 390.60, 585.90 and 130.64 is: 195.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.60 : 585.90 = 130.64 : x
  2. Step 2: Convert to fraction form
    390.60/585.90 = 130.64/x
  3. Step 3: Cross multiply
    390.60x = 585.90 × 130.64
  4. Step 4: Simplify right side
    390.60x = 76,541.98
  5. Step 5: Solve for x
    x = 76,541.98/390.60
  6. Step 6: Final answer
    x = 195.96

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.